Modified Formula for Hydrophilic Foam

ABSTRACT

The present invention provides a modified formula to make a hydrophilic foam. In some embodiments this modified formula adds a filler which causes the foam to become less absorptive, which has the benefit of making available to the skin more makeup or other products, while also providing a superior esthetic application of makeup on the skin. In other embodiments the modified formula makes the hydrophilic foam easier to clean and reduces the staining propensity of the foam. In other embodiments the modified formula uses an additive to the properties or usability of the foam in some way. Providing the filler and additive can be done in combination or separately depending on the desired benefits or properties of the foam. In some embodiments the foam is fashioned into a shape suitable for makeup application.

This application is a Non-Provisional patent application claimingpriority to and the benefit of U.S. Provisional Application No.62/722,801, filed Aug. 24, 2018, and having a title of “HydrophilicFoam.” The contents of the above-identified application is relied uponand incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a modified formula for making ahydrophilic foam which uses fillers or additives to enhance certainfeatures of the hydrophilic foam.

Typically hydrophilic polyurethane foams are made by directly reacting adiisocyanate with a polyol. Similarly, hydrophilic polyurea foams areoften made by directly reacting a diisocyanate with a polyamine. Both ofthese reactions are often neat, such that they use little to no aqueoussolution. The lack of a substantial aqueous solution can limit theability to use surfactants or other additives which are only soluble inan aqueous media, or which need an aqueous solution in order toemulsify. The inability to use certain additives which may havebeneficial properties or effects on the foam can be a limitation to thistechnology.

In other cases a diisocyanate pre blend (known as pre-polymer) is mixedwith an aqueous solution to form the hydrophilic foam. Depending onadditives in the aqueous solution this can create ureas, carbamates,carbonates, or mixtures of these functional groups.

When making hydrophilic foams, the isocyanate pre-polymers which aretypically used are either toluene diisocyanate (TDI) or methylenediphenyl diisocyanate (MDI). The aqueous solution is often comprised ofat least one surfactant, a preservative, and often additionalingredients to help control cell size. Additives are often used tocreate a fine soft cell cosmetic sponge.

Often to add firmness, measured in density, a filler is added to theaqueous solution. Typically the higher the amount of solid the more firmthe foam. In addition to fillers which add firmness, sometimes theinclusion of various surfactants or other additives will affect the cellformation of the inner matrices of the resulting foam structure. As anexample, the inclusion of an emulsifier to the aqueous solutiontypically has a dramatic increase in foam softness. This effect may beattributed to the fact that these emulsifiers affect the foam structurecell size, typically resulting in a finer tighter cell structure.Conversely, other surfactants or emulsifiers will typically increase thecell size and create a stiffer or more firm foam. Various surfactantsare generally used in the formulation of creams, soaps, cleansers,shampoos and the like to help in the emulsification of oils and such.Other additives, such as retinol (or vitamin A₁), hyaluronic acid,niacinamide, ceramide, peptides, curcuminoids, calcium, glycolic acid,argan oil, oils, caffeine, salicylic acid, alpha-hydroxy acid, and greentea can also be used.

Hydrophilic polyurethane foam technology is typically the preferredsponge material to apply makeup. Specifically, the foam is often used toapply makeup, foundation, blush, cream, and liquid makeup products tothe face and body. Hydrophilic foam is normally used as a makeupapplicator because of its inherent ability to absorb material, such asmakeup, creams, lotions, or other water based chemicals, into the foammatrix. This absorption is opposed to conventional urethane foam whichoften tends to be more hydrophobic and non-absorbent. Cosmetic brushes,which have long been a favored tool to apply makeup, have seen a loss ofmarket share likely due in part to hydrophilic foam sponges.

Due to the inherent absorbent nature of the hydrophilic foam sponge,some in the cosmetic industry believe that the sponge has a tendency toover absorb and also retain an excess amount of the makeup. The users ofthe hydrophilic foam sponges often complain that the makeup stays in thesponge and does not apply, lay down, or pay off onto to the user's face.Also, users often complain that they are required to use an excessamount of liquid or powder product since it is retained in the sponge.This excess makeup is generally wasted when the user washes the foamafter use. Even with washing, residues of the makeup can stick to thehydrophilic sponge causing it to stain and appear dirty which can be aserious detriment, especially for beauty products.

While the texture and feel of a cosmetic sponge is desirable andpreferred, the over absorption and excess product usage is not. Theexcessive usage and staining potential of makeup or other liquid/creamproducts is often perceived as a negative and detracts from the value ofthe sponge.

Accordingly, what is needed is a modified formula to make thehydrophilic foam sponge less absorptive and therefore make available tothe skin more makeup and additionally provide a superior estheticapplication of makeup on the skin, as well as foams which are easier toclean such that they do not stain after use. Additionally, the abilityto supplement additives which have beneficial properties to the skin orto the foam itself is desired.

SUMMARY OF THE INVENTION

The present invention relates to a modified formula for making ahydrophilic foam. In some embodiments the hydrophilic foam is made bymixing a prepolymer and an aqueous solution comprising at least onefiller which comprises about 20% to about 60% of the aqueous solution byweight.

In some embodiments the prepolymer is diisocyanate monomers. In someembodiments there are more than one filler. In some embodiments withmore than one filler, each filler comprises about 20% to about 60% ofthe aqueous solution by weight and in other embodiments the combinedweight of all the fillers comprise about 20% to about 60% of the aqueoussolution by weight.

In some embodiments the hydrophilic foam is made by mixing a prepolymerand an aqueous solution comprising at least one filler which comprisesabout 20% to about 60% of the aqueous solution by weight and at leastone additive.

In other embodiments the hydrophilic foam is made by mixing a prepolymerand an aqueous solution comprising at least one additive which comprisesless than about 15% of the aqueous solution by weight. In otherembodiments the hydrophilic foam is made by mixing a prepolymer and anaqueous solution comprising at least one additive which comprises lessthan about 15% of the aqueous solution by weight and at least one fillerwhich comprises about 20% to about 60% of the aqueous solution byweight.

In some embodiments there is more than one filler. In some embodimentswith more than one additive, each additive comprises less than about 15%of the aqueous solution by weight and in other embodiments the combinedweight of all the additives comprise less than about 15% of the aqueoussolution by weight.

In some embodiments the additive has a self cleaning effect, in othersan antimicrobial or antibacterial effect, in others a skin care effect,and in others an effect on the foam structure. In some embodiments theadditive is solubilized in water when wetted and applied to the skinwhen the foam is used.

In some embodiments the foam is dried after mixing the prepolymer andthe aqueous solution in order to remove excess water. In someembodiments the drying is completed using an oven, in others amicrowave, and in others the foam is dried in air. In some embodimentsthe drying is at room temperature and in others the foam is heated todry.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a hydrophilic foam manufacture according to one embodimentof the invention.

FIG. 2 shows a flowchart depicting one embodiment of a method forproviding the hydrophilic foam manufacture shown in FIG. 1.

FIGS. 3 and 4 show results from using a calcium silicate filler in theformation of a hydrophilic foam similar to the manufacture shown FIG. 1.

FIGS. 5 and 6 show results from using a diatomaceous earth filler in theformation of a hydrophilic foam similar to the manufacture shown FIG. 1.

FIGS. 7 and 8 show results from using a K1 glass spheres filler in theformation of a hydrophilic foam similar to the manufacture shown FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a modified formula for making ahydrophilic foam which used fillers or additives to enhance certainfeatures of the hydrophilic foam. In some embodiments the modifiedformula makes the hydrophilic foam less absorptive and therefore makesavailable more of the material which was absorbed by the foam. In otherembodiments the modified formula makes the hydrophilic foam easier toclean and reduces the staining propensity of the foam. In otherembodiments additives are included to enhance the foam or the experienceof using the foam.

In many embodiments below, the foam is shaped into a sponge shape formakeup application. While this invention focuses on foam sponges formakeup application it is also envisioned to be used for any applicationwhere typical hydrophilic foams absorb and contain an excess of materialwhich is meant to be transferred by the foam, such as foam sponges usedfor cleaning. In this invention, makeup refers to any material commonlyused in the cosmetic industry such as powder, foundation, cream, lotion,blush, concealer, primer, highlighter, rouge, gloss, or similarmaterials.

FIG. 1 shows a hydrophilic foam manufacture according to one embodimentof the invention. The manufacture may be a sponge, blender, or any typeof applicator for applying makeup or other substances. Some embodimentsof the invention optimize the payoff of the applied substances byreducing absorption and retention of the manufacture. While FIG. 1 showsone manufacture of a hydrophilic foam, the invention described below maybe of any size, shape, or dimension.

In some embodiments a prepolymer solution consisting of isocyanatemonomers is combined with a polyamine, and in other embodiments theisocyanate prepolymer is combined with a polyol. In some embodiments theisocyanate is a diisocyanate. Examples of diisocyanates are toluenediisocyanate (TDI) and methylene diphenyl diisocyanate (MDI). In otherembodiments more than two isocyanates are found on each monomer, such astri- or tetraisocyanate monomers. Monomers with different number ofpolymerization points allows for differing polymerization patterns andthus foam structures, and thus having different embodiments with thesedifferent monomers is essential for manufacturing foams whose structuraldiversity matches the diversity of the foam application.

In some embodiments the hydrophilic foam is made by combining theprepolymer with an aqueous solution. In some embodiments the aqueoussolution comprises at least one filler, at least one surfactant, atleast one preservative, at least one coloring agent, additionalingredients to help control cell size, or combinations thereof. In thispatent the term constituents refers to any of the different materialswhich are added to water to form the aqueous solution.

FIG. 2 displays a flowchart describing the method used to make oneembodiment of the invention with an aqueous solution. The first stepinvolves adding the constituents to water to form the aqueous solution(1). In some embodiments these constituents are soluble in water. Inmany embodiments the filler, being one of the constituents, is mostlyinsoluble in water. The amount of material combined together to form theaqueous solution is determined by weight percent for each component.Next, the prepared aqueous solution and isocyanate are mixed togetherusing a pre-determined ratio of each component (2). The ratio of aqueoussolution to isocyanate is determined by weight. After the reaction isallowed to occur between the aqueous layer and the isocyanate (3) theresulting foam is dried in to remove excess water (4). Finally, the foamis formed into the desired sponge shape (5). Each of these steps arediscussed in more detail below, as well as other embodiments made byalternative methods.

Many embodiments have the addition of a filler to increase thehydrophobicity of the foam. In some embodiments the filler is added tothe aqueous solution, in others the filler is added to the isocyanateprepolymer, and in other embodiments the filler is added separately. Inmany embodiments adding higher percentages of the selected fillerscauses the hydrophilicity of the foam to become reduced. This decreasein hydrophilicity typically leads to a decrease in foam absorbency aswell. The reduction in hydrophilicity, and thus increase inhydrophibicity, leads to a greater payoff of the material absorbed ontothe skin or other surfaces.

For the purposes of this invention, fillers include generallyhydrophobic compounds which are added to the foam construct. In manyembodiments the fillers include powdered inorganic compounds generallyinsoluble in water. Examples of fillers which fall under the currentinvention are calcium silicate, calcium metasilicate mineral(Wollastonite), aluminum silicate, magnesium silicate, diatomaceousearth (celite), glass spheres, silica, alumina, and combinationsthereof. In some embodiments only one filler is used as a means ofhaving a simpler foam with less need for storing and maintaining a widevariety of fillers, and in other embodiments more than one filler isused in order to give benefits from various filler materials. Thedifferent types of fillers have different benefits due to the diversechemical composition, physical characteristics, and chemicalcharacteristics. For instance, the density of Wollastonite is greaterthan hollow glass spheres, as these glass spheres contain significantamounts of air trapped within the external perimeter. Thus, foams withthe same volume of Wollastonite and glass spheres would comprisesignificantly less weight of glass spheres versus Wollastonite.

In some embodiments the fillers used are fine powders with an averageparticle size under 10 microns, in other embodiments the averageparticle size is 10-50 microns, in other embodiments the averageparticle size is 50-100 microns, and in other embodiments the averageparticle size is over 100 microns. The different chemicals with eachhave different typical particle sizes and effectiveness at thesedifferent sizes. For example, Nyco ASPECT® 4000 Wollastonite has anaverage particle size of 16 microns, whereas Celite® 545 has an averageparticle size of 20-100 microns. Powders under 10 microns are useful foreffectively mixing throughout the foam, but can have issues withcontainment if static electricity is present. Larger 100 micron powdershave less propensity to get dispersed with static electricity, but willmix and disperse within the foam less effectively.

In some embodiments the glass of glass spheres is borosilicate glass, inother embodiments the glass is soda-lime glass, and in other embodimentsthe glass is a combination of borosilicate and soda-lime glass. In someembodiments the glass spheres are solid glass spheres and in otherembodiments they are hollow glass spheres, comprising an externalperimeter of glass with gas inside. In some embodiments the glassspheres have an average particle size below 25 microns, in otherembodiments the glass spheres have an average particle size between 25and 50 microns, in other embodiments between 50 and 100 microns, and inother embodiments above 100 microns. As mentioned above, the smallerspheres better disperse within the foam but have a propensity to haveissues with static electricity, whereas the larger spheres have lesspropensity to get dispersed with static electricity, but will mix anddisperse within the foam less effectively. In some embodiments the cruststrength of the glass spheres is under 200 psi, in other embodiments thecrush strength is 200-1000 psi, in other embodiments the crush strengthis 1000-5000 psi, in other embodiments the crush strength is 5000-10,000psi, and in other embodiments the crush strength is over 10,000 psi. Thecrush strength of the spheres is generally associated with the size anddensity of the sphere, with the larger denser spheres having a greatercrush strength than the smaller hollow spheres. As makeup applicatorsare often squeezed during washing, having crush strength above 200 psihas been found to be important to avoid the spheres from breaking duringthis process. Other foam types which experience greater strain or forceshould have spheres with greater crush strength.

In embodiments which are made by the method described in FIG. 2, thefiller is one of constituents added to water which comprises the aqueoussolution (1). The amount of filler added is determined by weight of thefinal aqueous solution. In some embodiments the amount of filler used inthe foam is under about 30% of the aqueous solution by weight, in otherembodiments the amount of filler used is about 30% to about 60% of theaqueous solution by weight, and in other embodiments greater than about60% of the aqueous solution by weight. Levels above about 30% of theaqueous solution by weight of filler were especially successful atreducing the absorptive capacity of the foam. When using the foam withfiller content over about 30% of the aqueous solution by weight to applymakeup, there was less residual makeup retained in the foam. Using lessthan about 30% filler is useful when a firmer foam is desired but whenreducing the absorptive capacity is not a main focus. Embodiments withless than 30% filler are often used with an increase in otherconstituent amounts, where the embodiments focus on the benefits gainedby the other constituents. Embodiments above 60% are useful when a firmand non-absorbent foam is desired, such as for foam padding.

A variety of test were completed with hydrophilic foams made with anumber of fillers at varying weight percentages versus a control foamwith less than about 20% filler of the aqueous solution by weight and atest foam with about 60% filler of the aqueous solution by weight. Inthese tests the control typically deposited about 40% less material thanthe test foam. Several examples are detailed below using calciumsilicate, K1 glass spheres, and diatomaceous earth as fillers. For eachtest about 0.5 grams of a material, such as makeup, was absorbed by thefoam, and the amount of material subsequently deposited on a surface wasmeasured. The amount of material deposited, or resulting payoff, foreach instance is listed as both the absolute weight deposited, as wellas a percentage of the 0.5 grams of material absorbed. The higher losspercentage and higher weight loss in grams means more of the materialwas transferred from the foam, thus a greater payoff. Results tended tobe linear, in that the more amount of filler added, the greater thepayoff.

Example 1

FIGS. 3 and 4 show test results of the hydrophilic foam where calciumsilicate is the filler. The amount of calcium silicate used in this testranges from essentially 0% to about 50% of the aqueous solution byweight. The control foam with essentially 0% calcium silicate depositedabout 0.2 g, or about 40% of the total 0.5 g of material absorbed by thefoam. In contrast, when about 50% of the aqueous solution by weight ofcalcium silicate was added the foam deposited about 0.42 g, or about 84%of the total 0.5 g of material absorbed. A linear trendline with an R²value of 0.95 is displayed on each graph. FIG. 3 displays the weight ofmaterial deposited versus the percent by weight of calcium silicateadded, and FIG. 4 displays the percent loss.

Example 2

FIGS. 5 and 6 show test results of the hydrophilic foam wherediatomaceous earth is the filler. The amount of diatomaceous earth usedin this test ranges from essentially 0% to about 50% of the aqueoussolution by weight. The control foam with essentially 0% diatomaceousearth deposited about 0.18 g, or about 36% of the total 0.5 g ofmaterial absorbed by the foam. In contrast, when about 50% of theaqueous solution by weight of diatomaceous earth was added, the foamdeposited about 0.37 g, or about 74% of the total 0.5 g of materialabsorbed. A linear trendline with an R² value of 0.90 is displayed oneach graph. FIG. 5 displays the weight of material deposited versus thepercent by weight of diatomaceous earth added, and FIG. 6 displays thepercent loss.

Example 3

FIGS. 7 and 8 show test results of the hydrophilic foam where K1 glassspheres are the filler. The amount of K1 glass spheres used in this testranges from essentially 0% to about 12% of the aqueous solution byweight. The control foam with essentially 0% K1 glass spheres depositedabout 0.24 g, or about 48% of the total 0.5 g of material absorbed bythe foam. In contrast, when about 12% of the aqueous solution by weightof K1 glass spheres were added, the foam deposited about 0.44 g, orabout 88% of the total 0.5 g of material absorbed. A linear trendlinewith an R² value of 0.97 is displayed on each graph. FIG. 7 displays theweight of material deposited versus the percent by weight of K1 glassspheres added, and FIG. 8 displays the percent loss.

In some embodiments the addition of the filler enhances the capabilityof the hydrophilic foam to be used as a more efficient makeupapplicator. The filler allows the foam to absorb less makeup, releaseand apply more makeup to the skin, and still provide the desirable feeland texture of the applicator foam. In addition, the finish of themakeup on the skin is superior to conventional and current hydrophilicfoam sponges.

In some embodiments one or more additives are added to the hydrophilicfoam as a means of enhancing the foam in some way. For the purposes ofthis application, an additive is any chemical which is added to the foamwhich is not the isocyanate monomer, the water of the aqueous solution,the polyol or polyamine, or the filler. In some embodiments the additiveis a surfactant or other chemical which alters the formation of theinternal foam structure. In other embodiments the additive is a healthor beauty product which enhances use of the foam. In other embodimentsthe additive is a preservative. In other embodiments the additiveprotects the foam against bacteria or microbes. In some embodiments theadditive is a surfactant. Examples of additives as defined includeretinol (or vitamin A₁), hyaluronic acid, niacinamide, ceramide,peptides, curcuminoids, calcium, glycolic acid, argan oil, essentialoils, cosmetic oils, perfumes, fragrances, caffeine, salicylic acid,alpha-hydroxy acid, green tea, collagen, coloring agents, almond power,Shea fragrance, antibacterials, antimicrobials, charcoal, Germaben II,silane, antifoam emulsions, defoamers, surfactants, emulsifiers,Pluronic® L62, Pluronic® F88, Eumulgin® 1000, Eumulgin® B 2, Emulgade®1000 NI, or combinations thereof. In some embodiments, such as the onedemonstrated in FIG. 2, the additive is added to water to constitute theaqueous solution before mixing with the prepolymer, and in otherembodiments the additive is added to the reaction mixture directly.

In some embodiments the constituents only include the one or moreadditives and in other embodiments the constituents include both theadditive and filler. As mentioned above, embodiments with no filler areuseful when the benefits of the additive are the main focus, such asadditives which alter the physical properties of the foam. Embodimentswhich combine a filler and additive are useful when a firmer lessabsorbent foam is desired in combination with the benefits provided bythe additive. An example of this is a foam with a skin care additive incombination with a filler. The filler gives the foam less absorbency andprovides more payoff of the makeup, and this added payoff of the makeupprovides more payoff of the skin care additives which are solubilizedfrom the foam by the makeup. In some embodiments the constituentincludes only one additive and in other embodiments the constituentsincludes more than one additive. The use of only one additive isimportant when a single effect is desired, such as the addition of asurfactant to alter foam softness. The use of multiple additives isessential when a combined effect or more than one effect is desired,such as the addition of a surfactant to make a softer foam as well asthe addition of a fragrance or skin care product as a means of making amore versatile and healthy cosmetic foam sponge.

In some embodiments the amount of additive used is under about 1% of theaqueous solution by weight, in other embodiments between about 1% toabout 4% of the aqueous solution by weight, in other embodiments betweenabout 4% to about 10% of the aqueous solution by weight, and in otherembodiments greater than about 10% of the aqueous solution by weight.Often about 4% of the aqueous solution by weight or less of eachadditive is used, as this was found to generally achieve the bestbalance of cost and performance. However, different additives requiredifferent amounts to have maximum effect, which is why each range isessential. As an example, only a small amount, such as under about 0.5%of the aqueous solution by weight of an antimicrobial additive is neededto have the desired antimicrobial effect. On the other hand, typicallymore coloring, such as over about 5% of the aqueous solution by weightis needed to give a vibrant and rich color. Additionally, the chemicalconstitution of the additive effects the amount of additive the foam caneffectively hold while still being functional. For instance, the foamstructure in some embodiments can hold more solid or non-volatilematerial than a volatile material, as the volatile material is morelikely to escape though the porous foam structure.

In some embodiments, due to the chemical nature of the additive, theadditive is soluble in water. In these embodiments, the foam is wettedbefore use which solubilizes the additive and allows it to be releasedfrom the foam structure on the skin or other surface. In otherembodiments, due to the chemical nature of the additive, the additive isinsoluble in water. In these embodiments the makeup or other productapplied to the foam solubilizes the additive and allows it to bereleased from the foam structure on the skin or other surface along withthe product itself. In other embodiments the additives are released fromthe foam on their own, or without the need to be solubilized by water orproducts.

In some embodiments the additive is a skin care agent. Examples of skincare agents include retinol (or vitamin A₁), hyaluronic acid,niacinamide, ceramide, peptides, curcuminoids, calcium, glycolic acid,argan oil, essential oils, cosmetic oils, perfumes, fragrances,caffeine, salicylic acid, alpha-hydroxy acid, green tea, or combinationsthereof. Having skin care agents in the foam which are released whenapplying products to the skin is beneficial as it cares for and enhancesthe skin while applying the makeup or other product. This is beneficialto the consumer as it does not require the separate purchase of the skincare agents and does not require a second step or process of separatelyapplying the skin care product. Thus, the consumer gains the benefits ofthe skin care product with no extra financial or time burdens. Skin careproducts have a variety beauty or health effects, such as anti-wrinkle,anti-acne, moisturizing, anti-aging, UV protection, anti-oxidant,nutritional, and combinations thereof.

In other embodiments the additive is used for modifying the propertiesof the foam, or protect the foam from bacteria and microbials, and thustheir release is inconsequential. In some embodiments the additive isstill released via one of the methods described above, and in others theadditive is generally constrained within the foam construct. Examples ofadditives used to modify the properties of the foam are antibacterials,antimicrobials, charcoal, Germaben II, silane, antifoam emulsions,defoamers, surfactants, emulsifiers, coloring agents, Pluronic® L62,Pluronic® F88, Eumulgin® 1000, Eumulgin® B 2, Emulgade® 1000 NI, orcombinations thereof.

In some embodiments the properties of the foam which are modified arecell size, in some embodiments hardness, in some embodiments density, insome embodiments absorbency, in some embodiments cleaning properties,and in other embodiments color.

Especially important are embodiments where the foam has the ability torelease a significant amount of the product which was absorbed after theproduct is used, such that the foam does not appear dirty or stained, asthis is a problem with current hydrophilic foams. Foams which are madewith varying amount of surfactants such as Pluronic® L62, Pluronic® F88,Eumulgin® 1000, Eumulgin® B 2, Emulgade® 1000 NI, or combinationsthereof, have the unexpected effect of self-cleaning attributes suchthat they release products during rinsing significantly better than foamsponges without these additives and show significantly lessdiscoloration or staining. Depending on the surfactant, various amountsof material are optimal. In some embodiments less than about 0.5% of theaqueous solution by weight of these additives are used, in otherembodiments about 0.5%-1%, in other embodiments about 1%-1.5%, and inother embodiments about 1.5%-2.5% were used. In many of theseself-cleaning embodiments less than or equal to about 1.5-2.5% of theaqueous solution by weight of these additives are used as this was foundto be an optimal range. However, in some embodiments about 0.3%-1.5% wasfound to be an optimal range. Optimal ranges were determined bycomparing how the sponge felt, functioned, cleaned, and stained incomparison to a control sponge. Adding too much of the surfactantadditive affected the structure and feel of the sponge while adding tolittle reduced the cleaning effects. Different surfactants requireddiffering amounts to have the same effect. Additionally, the otherconstituents in the aqueous solution or in the foam in general effectthe function of the cleaning surfactants such that these ranges areessential. The use of an aqueous solution is important for theseembodiments as this solution is necessary to emulsify the additive.

In embodiments described by FIG. 2, after preparation of aqueoussolution (1) the aqueous solution and isocyanate are mixed together (2).In some embodiments the aqueous solution is added to the isocyanatewhich lowers the relative amount of water interacting with theisocyanate ensuring the isocyanate can react with other monomers afterreacting with the water. In other embodiments the isocyanate is added tothe aqueous solution which lowers the relative amount of isocyanate andensures significant production of carbon dioxide. In other embodimentsboth the aqueous solution and isocyanate are poured into a thirdreaction vessel. In all of the above mentioned mixing methods, the ratesof pouring effect the foam construction as slower pouring ensures fullyreaction of the materials being poured, while rapid pouring allows amixing of the materials and higher probabilities of inter-materialreactions.

In some embodiments the prepolymer and aqueous solution are mixed byweight ratios and in other embodiments by volume ratios. In someembodiments the ratio of the isocyanate to aqueous solution is anapproximately equal one-to-one ratio, and in other embodiments it is anunequal ratio. In some embodiments the ratio is up to about one partisocyanate to about two parts aqueous solution and in other embodimentsthe ratio is up to about one part isocyanate to about three partsaqueous solution. The amount of aqueous solution is essential to thecomposition of the foam for several reasons. First, since in manyembodiments the constituents are added to the aqueous solution, and theamount added is based on a percentage by weight of the aqueous solution,more aqueous solution leads to a greater amount of the constituents inthe final dried product. Second, adding more aqueous solution dilutesthe reaction which affects the rate of the reaction as well as foamconsistency. Adding more aqueous solution often results in thinner, morehomogeneous foams. This is because water reacting with the isocyanateproduces carbon dioxide, thus more water leads to a greater amount ofblowing agent causing a reduction in the density of the foam. It alsoleads to a decrease in the interactions of the isocyanate monomersleading to less cross-linking and chain elongation. Thus, foams withdifferent desired thickness, consistency, additive and filler amount,and homogeneity require varying ratios of isocyanate to aqueoussolution. Third, using more aqueous solution allows for a lower weightpercentage of the constituents required in the aqueous solution comparedto a more concentrated aqueous solution with similar final weightpercentages after drying. Having variability in the concentration of thevarious constituents is important as different materials have a limit totheir solubility, suspension, or emulsion in water. Fourth, using moreaqueous solution reduces overall costs as the prepolymer typically costsmore than the water and the other constituents in the aqueous solution.Thus, foams made with an approximately 1:1 aqueous solution:isocyanateratio are useful when a lower weight percentage of the constituents areneeded, when the constituents have good solubility or suspension abilityin water, when relative costs are not a significant concern, or when amore rapid reaction is desired. Contrast to this is foams made with anapproximately 3:1 aqueous solution:isocyanate ratio which are usefulwhen a higher weight percentage of the constituents are needed, when theconstituents have poor solubility or suspension ability in water, whenrelative costs are a significant concern, or when a more rapid reactionis not significant. Foams made with an approximately 2:1 aqueoussolution:isocyanate ratio are useful when an intermediate balance isdesired.

After initial mixing, the reaction is allowed to occur (3). The reactionbetween isocyanates and water is spontaneous at ambient temperature,exothermic, and results in the production of carbon dioxide which istypically used as an internal blowing agent. Depending on theconsistency and structure of the foam these various parameters can bealtered based on reaction conditions. In some embodiments this processis completed by stirring at ambient temperature (about 25° C.). Thismethod uses the least amount of energy as heating or cooling is notrequired. In some embodiments, in order to slow down the reaction andensure proper mixing of the reactants the reaction is cooled to betweenabout 25° C. and about 0° C. Keeping the reaction above about 0° C. isimportant as this prevents the aqueous layer from freezing. In someembodiments the aqueous solution and isocyanate are pre-cooled beforemixing to ensure the reaction temperature does not significantlyincrease, in other embodiments only the material not being poured iscooled, and in other embodiments the reaction is cooled after theaddition of the materials. In other embodiments, as a means of speedingup the reaction and forcing rapid interactions the reaction is heatedabove about 25° C. but below about 100° C. Keeping the reaction belowabout 100° C. is important as it keeps the aqueous layer from boilingand also keeps the reaction from reacting too rapidly or becomingdangerous. Similar to embodiments where the reaction is cooled theindividual reactants are heated separately before the mixing in someembodiments, or after mixing in other embodiments.

As the reaction produces carbon dioxide in some embodiments the reactionis completed under pressurized conditions to ensure that the carbondioxide gas is contained within the foam structure when forming suchthat the gas acts as an internal blowing agent. In other embodiments analternative blowing agent is added to the reaction. These alternativeblowing agents comprise the gasses consisting of external carbondioxide, oxygen, nitrogen, argon, air, or combinations thereof.

In some embodiments, after the reaction is complete, the resultant foamis dried to drive off the excess water from the aqueous solution notused in the reaction. In some embodiments the drying process iscompleted in a microwave reactor, as in step 4 of FIG. 2. In otherembodiments the drying process is completed in an oven, and in otherembodiments the drying process is completed via drying in air. In someembodiments where the foam is dried in the microwave or oven the foam isdried under heated conditions. In some embodiments the foam is heatedfrom about 25-50° C., in other embodiments from about 50-100° C., and inother embodiments over about 100° C. The chemical nature of the foamitself as well as the constituents in the aqueous solution determinesthe ideal temperature for drying. When using little to no constituentsin the aqueous solution which need to be preserved after drying highertemperatures (about 100° C. or higher) can be used as this mostefficiently drives off the water at or above its boiling point. However,some constituents are not stable at higher temperatures, thustemperatures ranging from about 25-100° C. would need to be used.Similarly, the stability of certain urea, carbamate, or carbonate bondsare temperature dependent and could react with water molecules at highertemperatures, destroying the stability and structure of the foam.

In some embodiments, after drying, the foam is formed into a desiredshape (5), such as the shape shown in FIG. 1. In other embodiments thefoam reaction takes place in a vessel which confines the reaction to thedesired shape such that no forming is required. For embodiments wherethe foam is formed, this process is completed by the methods consistingof cutting, burning, molding, or combinations thereof.

While the present invention has been particularly described, it isevident that many alternatives, modifications, and variations will beapparent to those skilled in the art in light of the foregoingdescription. These descriptions and drawings are exemplary of specificembodiments only and are not intended to be limiting to the scope of theinvention defined in the claims. It is therefore contemplated that theclaims will embrace any such alternatives, modifications, and variationsas falling within the true scope and spirit of the present invention.

What is claimed:
 1. A hydrophilic foam comprising: a prepolymer; anaqueous solution comprising water and at least one filler; wherein saidat least one filler comprises about 20% to about 60% of the aqueoussolution by weight; wherein said prepolymer and said aqueous solutionare mixed together to form said hydrophilic foam.
 2. The hydrophilicfoam of claim 1, wherein said prepolymer is a mixture of diisocyanatemonomers.
 3. The hydrophilic foam of claim 1, further comprising morethan one filler and wherein each of said fillers comprise about 20% toabout 60% of the aqueous solution by weight.
 4. The hydrophilic foam ofclaim 1, further comprising more than one filler and wherein thecombined weight of said fillers comprise about 20% to about 60% of theaqueous solution by weight.
 5. The hydrophilic foam of claim 1, whereinat least one filler is selected from the group consisting of calciumsilicate, calcium metasilicate mineral, aluminum silicate, magnesiumsilicate, diatomaceous earth (celite), glass spheres, silica, alumina,and combinations thereof.
 6. The hydrophilic foam of claim 1, furthercomprising at least one additive.
 7. The hydrophilic foam of claim 6,wherein at least one additive has a self-cleaning effect on saidhydrophilic foam.
 8. A hydrophilic foam comprising: a prepolymer; anaqueous solution comprising water and at least one additive; whereinsaid at least one additive comprises less than about 15% of the aqueoussolution by weight; wherein said prepolymer and said aqueous solutionare mixed together to form said hydrophilic foam.
 9. The hydrophilicfoam of claim 8, further comprising more than one additive and whereineach of said additives comprise less than about 15% of the aqueoussolution by weight.
 10. The hydrophilic foam of claim 8, furthercomprising more than one additive and wherein the combined weight ofsaid additives comprise less than about 15% of the aqueous solution byweight.
 11. The hydrophilic foam of claim 8, wherein at least oneadditive is defined by the label consisting of surfactant, skin careagent, antibacterial, antimicrobial, defoamer, coloring agent, charcoal,or combinations thereof.
 12. The hydrophilic foam of claim 8, wherein atleast one additive is selected from the group consisting of retinol(vitamin A₁), hyaluronic acid, niacinamide, ceramide, peptides,curcuminoids, calcium, glycolic acid, argan oil, essential oils,cosmetic oils, perfumes, fragrances, caffeine, salicylic acid,alpha-hydroxy acid, green tea, Germaben, silane, Pluronic® L62,Pluronic® F88, Eumulgin® 1000, Eumulgin® B 2, Emulgade® 1000 NI,charcoal, or combinations thereof.
 13. The hydrophilic foam of claim 8,wherein at least one additive is water soluble such that is itsolubilized and released when the foam is wetted.
 14. The hydrophilicfoam of claim 8, wherein at least one additive is a surfactant whichcomprises about 0.3% to about 2.5% of the aqueous solution by weight andhas a self-cleaning effect on said hydrophilic foam.
 15. The hydrophilicfoam of claim 8, further comprising at least one filler that comprisesabout 20% to about 60% of the aqueous solution by weight.
 16. A methodfor preparing a hydrophilic foam comprising the steps of mixing at leastone filler with water to form an aqueous solution; wherein said at leastone filler comprises about 20% to about 60% of the aqueous solution byweight percent; mixing said aqueous solution with a prepolymer; allowinga reaction to occur between said prepolymer and said aqueous solutionfor creating said hydrophilic foam.
 17. The method for preparing ahydrophilic foam of claim 16, further comprising the step of selectingat least one filler from the group consisting of calcium silicate,calcium metasilicate mineral, aluminum silicate, magnesium silicate,diatomaceous earth (celite), glass spheres, silica, alumina, andcombinations thereof.
 18. The method for preparing a hydrophilic foam ofclaim 16, further comprising the step of mixing at least one additivewith said at least one filler and said water to form said aqueoussolution.
 19. The method for preparing a hydrophilic foam of claim 16,further comprising the step of drying said hydrophilic foam to removeexcess water, and wherein said step of drying said hydrophilic foam iscompleted by selecting from the method consisting of oven drying,microwave drying, air drying, and combinations thereof.
 20. The methodfor preparing a hydrophilic foam of claim 16, further comprising thestep of forming said hydrophilic foam into a desired shape.